This invention relates to a process for preparing N-vinyl carbazoles. These compounds have many uses, for example those described by S. Tazuke and S. Okamura in "Vinylcarbazole Polymers" in the Encyclopedia of Polymer Science and Technology, Volume 14, page 281 to 304, published in 1971, and references cited therein, all of which are incorporated herein by reference. The preparation of various N-vinyl carbazoles is also described in this reference.
Carbazole has been deprotonated with bases and subsequently reacted with acetylene [as described by H. Beller, et al., British Patent No. 641,437, issued in 1950; see Chemical Abstracts, Vol. 45, p 8044i (1950)]; ethylene oxide [as described by I. P. Zherebtsov and V. P. Lopatinskii, in Izv. Tomsk. Politekt Inst., Volume 196, page 189, published in 1969; see Chemical Abstracts, Vol. 72, 111210 Z (1970)]; 2-chloroethanol/acetic anhydride [as described by R. G. Flowers, et al., published in the Journal of the American Chemical Society, Vol. 70, page 3019 (1948)]; vinyl chloride [as described by W. Reppe, et al., published in Annalen, Vol. 601, page 128 in 1956; see Chemical Abstracts, Vol. 51, 9584a (1957)]; and vinyl acetate [as described by V. P. Lopatinskii, et al., published in Methody Poluch Khim., Reaktiv. Prep., Number 22, page 200 in 1970; see Chemical Abstracts, Vol. 77, 139714 (1972)]. Carbazole has also been reported to react with the tosylate of 2-chloroethanol to form .beta.-chloroethylcarbazole which is subsequently treated with base to give N-vinyl carbazole [as described by T. Ishii and M. Hayaski, published in the Journal of the Society of Organic Synthetic Chemists of Japan, Vol. 7, page 41, in 1949; see Chemical Abstracts, Vol. 44, 3970i (1950)]. Carbazole has been reacted with ethylene and various vinyl ethers in the presence of catalysts to produce N-vinylcarbazole as reported by E. W. Stern and M. L. Spector, in U.S. Pat. No. 3,564,007, issued in 1971; K. Matsurshiro and T. Oda, Japanese Pat. No. 749,466, issued in 1974; [see Chemical Abstracts, Vol. 83, P148000j (1975)]; and V. A. Anfinogenor, et al., published in the Zhurnal Org. Khim. Vol. 14, page 1723 in 1978; see Chemical Abstracts, Vol. 90, 38764y (1979).
In addition, V. D. Filimonov, et al., described the addition of carbazole to acetaldehyde in the presence of an alcohol to produce the intermediate .alpha.-alkoxyethyl N-carbazoles which are subsequently contacted with chloride in pyridine to produce N-vinyl carbazole [see Zhurnal, Org. Khim., Vol. 14, page 2607, in 1978; Chemical Abstracts, Vol. 90, 103763p (1979)].
Most of these reactions require isolation of intermediates, high pressures and temperatures, special equipment and/or long reaction times.
It is an object of this invention to describe a process for the preparation of substituted N-vinyl carbazoles.
It is a further object of this invention to describe a process that can be performed at atmospheric pressure in glassware, without the need for isolation of intermediates.